.video-wrap{
    width: 100%;
    margin-top: 10px;
    display: flex;
    flex-wrap: wrap;
    cursor: pointer;
    justify-content: space-between;
    .video-item  {
       //TODO:grid布局有溢出撑开子元素的问题
    //flex布局宽度计算:  m = 间隙 * n(一行的个数) / n
      width: calc(20% - 16px); //每个宽度 calc(100/n - m)
      margin-bottom: 20px;
      &:nth-of-type(5n) {
        margin-right: 0;
      }
  }
}